Among the following, which one is the **least** water-efficient crop?

Gives a quantitative crop water requirement for sugarcane in mm (1500–2500 mm), a direct measure of depth of water needed over the growing season.

Convert mm to liters per unit area (1 mm = 1 L/m²) and then divide by typical yield (kg/m² or kg/ha from external sources) to estimate L/kg.

Provides a general physiological rule: about 400–500 litres of water are required to produce one kilo of plant dry matter.

Combine this dry-matter L/kg with data on the dry-matter fraction of harvested sugarcane (requires an external typical % dry matter) to infer irrigation L/kg of harvested produce.

States sugarcane is among crops with ‘very high’ water needs, implying its L/kg will be large compared with cereals.

Use this qualitative ranking to compare any L/kg estimate for sugarcane against known L/kg values for other crops (from external sources) to judge plausibility.

Notes sugarcane is predominantly cultivated in irrigated tracts and accounts for substantial production on limited area, implying intensive water input per area.

Combine the high area-based irrigation intensity with regional typical yields (external) to estimate L/kg and assess whether a given statement is consistent with irrigated cultivation.

Lists sugarcane explicitly as an example of an irrigated crop, reinforcing that irrigation-dominated water accounting applies to it.

Use irrigation-crop classification to justify using seasonal irrigation-depth figures (from evidence 1) rather than relying solely on rainfall for L/kg calculations.